Leaching properties of Pb, Cd, Zn, Cu at pH of 2-6 using different inorganic acids (hydrochloric acid, sulfuric acid, nitric acid) and organic acids (acetic acids, citric acid, malic acid, succinic acid) aiming at polluted sediment at downstream of a non-ferrous metal smelting enterprise is discussed. Results showed that leaching concentrations of 4 metals decreased with increasing pH. Among al...

The solvent extraction of gallium from a concentrated Jajarm Bayer process liquor containing 164.90 g/l of Na2O, 86.70 g/l of Al2O3 and 106.02 ppm of gallium was investigated using 10 vol.% Kelex100, a 7-alkyl substituted-8 hydroxyquinoline as an extractant, 10 vol.% etanol as a modifier and kerosene as a diluent. At (Vo :Va = 1.0:1.0) ...

Malate in beet discs treated in different salt solutions was labeled by a 30 min pulse of (14)CO(2), and subsequent changes in specific activity were followed for several hr. In treatments which resulted in net acid synthesis in response to excess cation absorption, malate specific activity fell slowly after removal of (14)CO(2). In solutions where no net acid synthesis occurred, and from which...

Colloid release and deposition in soils and sorption of inorganic and organic pollutants to soil colloids are strongly influenced by the composition and chemical heterogeneity of colloidal soil particles. To investigate the chemical heterogeneity of organic soil colloids at the particle scale, we used synchrotron scanning transmission X-ray microscopy (STXM) and C-1s near-edge X-ray absorption ...

Despite being of high biotechnological relevance, many aspects of organic acid excretion in filamentous fungi like the influence of ambient pH are still insufficiently understood. While the excretion of an individual organic acid may peak at a certain pH value, the few available studies investigating a broader range of organic acids indicate that total organic acid excretion rises with increasi...

Excised roots of barley (Hordeum vulgare, var. Campana) lost organic acids, amino acids, K(+), and Cl(-) within 15 minutes after initiation of anaerobic treatment or treatment with NaCN and 2,4-dinitrophenol. Initial loss of organic acids when roots were placed under N(2) is attributed to a decarboxylation reaction, possibly catalyzed by phosphoenolpyruvate carboxykinase. Organic and amino acid...

A method is described for the determination of total arsenic by hydride generation-atomic absorption spectrophotometry using a mixed acid as a pretreatment. Hydride generation is done by the flow-injection method. The authors investigated in detail the temperature and time of decomposition using inorganic, organic arsenic and environmental standard samples, pretreated with nitric-perchloric-sul...